基于数字岩心的低渗透砂岩储层导电性数值模拟研究

低渗透砂岩导电机理复杂,为了进一步研究其储层的导电性,以Micro-CT扫描的二维岩心图像的微观孔隙结构特征为基础,利用二值化阈值分割法、数学形态法提取连通孔隙,建立三维数字岩心模型,应用最大球算法建立数字岩心的孔隙网络模型;采用有限元法模拟数字岩心模型的导电特性,探讨孔隙结构、地层水矿化度、饱和度及润湿性等因素对储层岩石电性的影响规律。研究结果表明,在低渗透砂岩储层中地层因素与孔隙度满足阿尔奇公式;当含水饱和度为50%时,电阻率增大系数与含水饱和度交会图呈现2种不同的直线形态。该研究为低渗透砂岩储层电法测井解释提供了理论支撑。

砾岩低渗透油藏注入水中固体悬浮物的伤害实验

砾岩低渗透油藏储层非均质性强、孔喉半径小、矿物成分复杂,在注水开发中,回注水中固体悬浮物含量和粒径大小成为导致储层伤害的主要因素,而现有碎屑岩低渗透油藏注水水质推荐指标难以满足砾岩低渗透油藏,因此,需根据砾岩低渗透油藏储层特点,制定科学的注水水质指标。根据砾岩低渗透油藏储层孔隙结构及黏土矿物特性,采用CT扫描、扫描电镜及X射线衍射等实验方法,多角度分析了该类油藏潜在的注水伤害主要因素,同时根据颗粒堵塞理论,在注入过程中注入水中的固体悬浮物(SS),会堵塞孔喉通道导致渗透率下降,从而对砾岩低渗透岩心造成严重伤害。实验结果表明,SS质量浓度和粒径中值对不同渗透率的砾岩岩心的储层伤害差异较大,若要实现目标区块储层伤害率≤20%,当储层渗透率小于等于9.28 mD时,SS质量浓度≤1.43 mg/L,粒径中值≤1.9μm;当储层渗透率大于9.28 mD但小于46.9 mD时,SS质量浓度≤3.1 mg/L,粒径中值≤2.6μm;而储层渗透率大于等于117 mD时,可放宽到SS质量浓度≤5.1 mg/L,粒径中值≤4.8μm。

油田用烯烃磺酸盐液相色谱-质谱检测法

针对传统滴定检测法的灵敏度低、抗干扰能力差、检测周期长等不足,利用液相色谱串联四级杆质谱联用仪建立了油田用烯烃磺酸盐的检测方法。优化了检测条件,定量检测了烯烃磺酸盐产品、注入液和产出液中的烯烃磺酸盐。结果表明,检测烯烃磺酸盐的最佳条件为:阴离子型色谱柱;流动相为体积比55∶45的甲醇和8 mmol/L乙酸铵水溶液,等度洗脱;质谱检测器,条件为电喷雾离子源,负模式,雾化气压力30 psi、干燥气流速8 L/min、干燥气温度350℃、全扫描。该方法对烯烃磺酸盐产品、注入液和产出液的加标回收率分别为82.63%~96.37%、78.60%~95.41%、82.68%~95.72%,8 min即完成一次样品检测,且聚合物、微量原油等对检测结果影响较小。该方法可快速、灵敏的检测烯烃磺酸盐产品、注入液及采出液中目标物质的含量,抗干扰能力强。

NOISE INDUCED HEARING LOSS IN CHINA:A POTENTIALLY COSTLY PUBLIC HEALTH LSSUE

Hearing loss and tinnitus are among the most common consequences of long term noise exposure and re-main an under-addressed heath issue in most developing nations including China. The rapid industrializa-tion and life style changes in China increase the concern over noise exposure and noise induced hearing loss (NIHL). Research on NIHL in China is limited. The current paper reviews studies published in English and Chinese language literatures regarding noise exposure and NIHL in China. Their implication on the Chi-nese population is discussed. The possible utility of a research model such as the Dangerous Decibels? as a means to increase understanding of the scope of NIHL among the Chinese population, to educate the gener-al public in China (especially the young) about NIHL and its prevention, and to study effects of language and cultural factors on international information dissemination and behavioral interventions is proposed.